The heating lamp died on my cage for my red tail boa will he live overnight without a heating lamp?

You're boa will be fine for the night. Since snakes are cold blooded their body temperature changes with the temperature of the air around them, a heated house can suit a snake just fine without the heat lamp (I mean the house could sustain it for some time but fix the lamp) . Snakes in the wild snakes can go hibernate in low temperatures and live for a while, you're snake will be fine in a regular house.